Java tutorial
/* * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing; import java.awt.Component; import java.awt.Container; /** * This interface is implemented by components that have a single * JRootPane child: JDialog, JFrame, JWindow, JApplet, JInternalFrame. * The methods in this interface are just <i>covers</i> for the JRootPane * properties, e.g. <code>getContentPane()</code> is generally implemented * like this:<pre> * public Container getContentPane() { * return getRootPane().getContentPane(); * } * </pre> * This interface serves as a <i>marker</i> for Swing GUI builders * that need to treat components like JFrame, that contain a * single JRootPane, specially. For example in a GUI builder, * dropping a component on a RootPaneContainer would be interpreted * as <code>frame.getContentPane().add(child)</code>. * <p> * As a convenience, the standard classes that implement this interface * (such as {@code JFrame}, {@code JDialog}, {@code JWindow}, {@code JApplet}, * and {@code JInternalFrame}) have their {@code add}, {@code remove}, * and {@code setLayout} methods overridden, so that they delegate calls * to the corresponding methods of the {@code ContentPane}. * For example, you can add a child component to a frame as follows: * <pre> * frame.add(child); * </pre> * instead of: * <pre> * frame.getContentPane().add(child); * </pre> * <p> * The behavior of the <code>add</code> and * <code>setLayout</code> methods for * <code>JFrame</code>, <code>JDialog</code>, <code>JWindow</code>, * <code>JApplet</code> and <code>JInternalFrame</code> is controlled by * the <code>rootPaneCheckingEnabled</code> property. If this property is * true (the default), then calls to these methods are * forwarded to the <code>contentPane</code>; if false, these * methods operate directly on the <code>RootPaneContainer</code>. This * property is only intended for subclasses, and is therefore protected. * * @see JRootPane * @see JFrame * @see JDialog * @see JWindow * @see JApplet * @see JInternalFrame * * @author Hans Muller * @since 1.2 */ public interface RootPaneContainer { /** * Return this component's single JRootPane child. A conventional * implementation of this interface will have all of the other * methods indirect through this one. The rootPane has two * children: the glassPane and the layeredPane. * * @return this components single JRootPane child. * @see JRootPane */ JRootPane getRootPane(); /** * The "contentPane" is the primary container for application * specific components. Applications should add children to * the contentPane, set its layout manager, and so on. * <p> * The contentPane may not be null. * <p> * Generally implemented with * <code>getRootPane().setContentPane(contentPane);</code> * * @exception java.awt.IllegalComponentStateException (a runtime * exception) if the content pane parameter is null * @param contentPane the Container to use for the contents of this * JRootPane * @see JRootPane#getContentPane * @see #getContentPane */ void setContentPane(Container contentPane); /** * Returns the contentPane. * * @return the value of the contentPane property. * @see #setContentPane */ Container getContentPane(); /** * A Container that manages the contentPane and in some cases a menu bar. * The layeredPane can be used by descendants that want to add a child * to the RootPaneContainer that isn't layout managed. For example * an internal dialog or a drag and drop effect component. * <p> * The layeredPane may not be null. * <p> * Generally implemented with<pre> * getRootPane().setLayeredPane(layeredPane);</pre> * * @param layeredPane the layered pane * @exception java.awt.IllegalComponentStateException (a runtime * exception) if the layered pane parameter is null * @see #getLayeredPane * @see JRootPane#getLayeredPane */ void setLayeredPane(JLayeredPane layeredPane); /** * Returns the layeredPane. * * @return the value of the layeredPane property. * @see #setLayeredPane */ JLayeredPane getLayeredPane(); /** * The glassPane is always the first child of the rootPane * and the rootPanes layout manager ensures that it's always * as big as the rootPane. By default it's transparent and * not visible. It can be used to temporarily grab all keyboard * and mouse input by adding listeners and then making it visible. * by default it's not visible. * <p> * The glassPane may not be null. * <p> * Generally implemented with * <code>getRootPane().setGlassPane(glassPane);</code> * * @param glassPane the glass pane * @see #getGlassPane * @see JRootPane#setGlassPane */ void setGlassPane(Component glassPane); /** * Returns the glassPane. * * @return the value of the glassPane property. * @see #setGlassPane */ Component getGlassPane(); }